Showing papers by "Yang-Tse Cheng published in 2000"
TL;DR: In this article, the authors derived simple scaling relationships for loading and unloading curve, contact depth, and hardness, and derived a scaling theory for indentation in power-law creep solids using self-similar indenters.
Abstract: Using dimensional analysis and finite element calculations, we derive simple scaling relationships for loading and unloading curve, contact depth, and hardness. The relationship between hardness and the basic mechanical properties of solids, such as Young's modulus, initial yield strength, and work-hardening exponent, is then obtained. The conditions for 'piling-up' and 'sinking-in' of surface profiles during indentation are determined. A method for estimating contact depth from initial unloading slope is examined. The work done during indentation is also studied. A relationship between the ratio of hardness to elastic modulus and the ratio of irreversible work to total work is discovered. This relationship offers a new method for obtaining hardness and elastic modulus. Finally, a scaling theory for indentation in power-law creep solids using self-similar indenters is developed. A connection between creep and 'indentation size effect' is established.
159 citations
TL;DR: In this article, the relationship between hardness and cone angle of conical indenters was studied using finite element analysis for elastic-plastic solids with work-hardening, and compared with the present simulation results, slip line theory, and experimental results.
Abstract: The relationship between hardness and cone angle of conical indenters was studied using finite element analysis for elastic–plastic solids with work-hardening. Comparisons were made between the present simulation results, slip line theory, and experimental results. Tabor's concept of representative strain based on indentation experiments in metals (The Hardness of Metals, Oxford, 1951) was shown to be applicable to a wide range of materials. The relative size of plastic zone with respect to the contact radius was found to influence the variation of hardness with indenter cone angle. The method proposed by Atkins and Tabor [J. Mech. Phys. Solids, 13, 149 (1965)] for constructing stress-strain curves using representative strains was also examined, and the conditions under which the method is valid were obtained.
45 citations
TL;DR: In this paper, the relationships between hardness, elastic modulus, final contact depth, and the work of indentation are extended to conical indentation in elastic-plastic solids with various cone angles.
Abstract: Using dimensional analysis and finite element calculations, the relationships between hardness, elastic modulus, final contact depth, and the work of indentation are extended to conical indentation in elastic-plastic solids with various cone angles. These relationships provide new insights into indentation measurements. They may also be useful to the interpretation of results obtained from instrumented indentation experiments.